1. Field of the Invention
The present invention relates, in general, to a channel equalizer, a method and a computer program for equalizing a channel.
2. Description of the Related Art
A physical channel of a digital communication system such as a high definition television (HDTV) system generally exists in free space. An ideal channel may be implemented in a vacuum state, i.e., without a medium. However, since a transmission path of a channel signal may be refracted due to atmospheric changes, meteorological changes, etc., the signal may be transmitted to a receiver via multiple paths.
Multiple paths may include fixed multiple paths and time-dependent multiple paths, for example. Fixed multiple paths are paths on which a transmitted signal is reflected or refracted due to natural features or structures, such as a mountain, cliff, etc. Time-dependent multiple paths are paths by which a transmitted signal is propagated differently due to moving vehicles such as airplanes and cars, for example.
When a signal is transmitted over various paths with different propagation times, the signal (received through such multiple paths) may have inter symbol interference (ISI). ISI typically deteriorates performance of high-speed digital communication systems such as HDTV systems.
Accordingly, a channel may generate signal distortion. Since such signal distortion may cause bit detection errors in a receiving side when signals are transmitted according to conventional digital communication methodologies used in a HDTV, etc., an entire area of a picture may not be restored, and/or an erroneous picture may appear.
In an effort to solve these errors or problems with picture quality, an HDTV receiver may include a channel equalizer that processes transmission signals passed through a distorted channel, so as to compensate for the characteristic of the channel.